Most 945s I've seen in implementation have the DVD/drive bay as PATA
bridged to SATA.
But, this is an irrelevant conversation.
For drives controlled by ata_piix, they will continue with the
"hotplug all the time" policy that the rest of libata has until
someone else patches that driver to mark the drives not hotpluggable
based on whatever method they want to use to determine that. As we
get more laptops implementing pure SATA drive bays we can refine
the patch to use ACPI events to turn the phy back on if
laptop vendors continue to use ACPI to generate insert/remove events.
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